Waterproof connection for spark-plugs.



' A. SCHMIDT.

WATERPROOF CONNECTION FOR SPARK PLUGS.

APPLICATION FILED NOV. 22. m1.

Pafented Apr. 1, 1919.

3&1, W ummm.

(Uta nu s UNITED STATES PATENT OFFICE.

ALBERT SCHMIDT, F FLINT, MICHIGAN, ASSIGNOR TO CHAMPION IGNITION COMPANY, OF FLINT, MICHIGAN, A CORPORATION OF MICHIGAN.

WATERPROOF CONNECTION FOR SPARK-PLUGS.

Specification of Letters Patent.

Application filed November 22, 1917. Serial No. 208,296.

To all whom it may concern:

Be it known that I, ALBERT SoHMnyr, a citizen of the Republic of France, residlng at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in Waterproof Connections for Spark-Plugs, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to water-proof connections for spark-plugs of the type in wh ch the insulator and terminal thereon are 1nclosed by a cap having connected thereto an insulatedconduetor in electrical connection with said terminal. It is the object of the present invention to provide a thoroughly weather-proof construction, one which is easily applied and taken off, which establishes good electrical connection and which is free from any stress upon the insulator which might cause the cracking or breaking of the same.

In the drawings: I

Figure 1 is a side elevation partly in section through the construction;

Fig. 2 is an elevation viewed at right angles to Fig. 1;

Fig. 3 is a plan view;

Fig. 4 is an enlarged section through the electrical terminal connection.

A is a spark-plug which may be of any suitable construction, but as shown is formed with a casing B having the projecting insulator C secured by an integral retaining flange D. My improvement comprises a hood or cap E which is recessed to fit over the projecting portion of the insulator C with suificient clearance to avoid contact therewith. This hood is preferably formed of insulating material and at its lower end may be provided with a gasket F of any sultable material for formin a sealing seat upon the casing B. Within t e recess and at the upper or inner end thereof is a terminal contact G, preferably in the form of ametallic spring which is adapted to bear against an electrical contact H on the end of the insulator C. I is an insulated conductor which passes into a lateral aperture in the hood E, a bared portion J of the conductor extending into the recess. To provide for quickly attachin this conductor to the terminal contact t e latter is mounted in a threaded bushing K which engages a correspondingly threaded portion of the hood so as to be adustable inward oroutward therein by arotatlve movement. The member K forms a clamp which may be tightened against the bared end J of the conductor, thereby establishlng good electrical connection and also form ng a retaining means which prevents the dlsengagement of the conductor from the hood. The spring terminal contact G is preferably arranged in a central recess in the ushing K and has its inner end attached by soldering or otherwise to the bushing so as to form good electrical connection, while the opposite end is in a position to contact with the terminal H. For securing the hood upon the sparkplug, there is provided an external clamping mechanism. This preferably comprises a sheet-metal member L embracing the hood, its lower edge engaging a shoulder M thereon and being also provided with laterallyextending arms N which at diametrically opposite points on the hood are provided with pivot bearings O. P is a yoke connected to Patented Apr. 1, 1919.

the pivot bearings 0 but slotted to permit of v vertical movement thereon. Q is a lever, preferably in the form of a bail pivotally attached at R to the yoke P and having a cammed or eccentric portion Sforengaging the arms N. The lower end of the yoke P is provided with inwardly-extending hooks T for engaging some portion of the spark-plug casing, such as the shoulder U beneath the polygonal head. With the construction as described, to engage the hood it is placed over the insulator so that the bearing or gasket F will fit against the casing B. The yoke P is then swung inward on its pivot 0 so as to engage the hooks T with the shoulder U. The bail Q is then turned upward, which causes the cams or eccentrics S to. bear against the arms N, drawing the yoke upward and exerting a clamping pressure against the hooks and shoulder U. The arms N are yielding and resilient and therefore permit of springing downward under the action of the cams so that the hood is re tained to its seat by resilient pressure. At the same time the contact spring. G will bear against the terminal H and will be placed under slight tension so as to maintain its contact under any jar or vibration to which the plug may be subjected. When thus secured the hood will completely exclude the water from access to the terminals so that all danger of short-circuiting is avoided. Another advantage is that the insulator is completely protected from shocks and is also free from an pressure save that transmitted through the terminal H which is connected with theinsulated electrode. Any expansion or contraction' due to change in temperature is permitted without increasing the stress and consequently danger of breaking the insulator is avoided.

What I claim'as my invention is:

.1. The combination with a spark-plug having a casing, a projecting insulator and electrical contact thereon, of a hood for inclosing said insulator said hood being detachably mountedv on said casing, and contact, an electrical conductor secured to said hood, a terminal contact electrically connected to said conductor and resiliently bearing against said contact on said insulator without direct pressure on said insulator, and means for clamping said hood to said casing.

2. The combination with a spar'k-plu having a casing, a projecting insulator and an electrical contact at the outer end thereof, of a hood for covering said insulator and contact free from direct bearing thereon, a resilient contact secured to said hood and removable therewith, said resilient contact being adapted to bear upon the contact upon said insulator, an insulated electrical conductor secured to said hood and electrically connected with said resilient terminal, and means for clamping said hood to the sparkplug casing.

3. The combination with a spark-plug having a casing, a projecting insulator and an electrical contact at the outer end thereof, of a hood for inclosing said insulator and contact without direct bearing thereon, an

insulated electrical conductor connected to sald hood, a resilient terminal contact electrically connected to said conductor and mechanically attached within said hood, said resilient contact being adapted to bear against the contact on said insulator, a yoke pivotally attached to said hood' and engageable with a shoulder on the spark-plug casing,and means for tensioning' said yoke to clam said hood upon said casing.

4. he combination with a spark-plug having a projecting insulator and an electrical contact thereon, of a .hood for inclosing said insulator and contact, means for clamping said hoodto the spark-plug Gasing, an insulated electrical conductor lat--.

erally inserted through an aperture in said hood and having a bared portion extending into the recess therein, member for cooperating with the contact on said insulator, and a member to which said resilient contact is attached adjustable within said hood to clamp the bared end of said a resilient contact electrode and to thereby secure and establish electrical connection therewith.

5. The combination with a spark-plug having a projecting insulator and a terminal ductor and a contact spring arranged in a recess in said adjustable member, being electrically connected thereto and having its free end in position to contact with the contact on said insulator.

'6. The combination with a spark-plug and an insulator projecting therefrom having a terminal contact at its outer end, of a hood for inclosing said insulator and contact, an insulated, electrical conductor engaging an aperture in said hood having a bared portion extending into the recess therein, a member having a threaded engagement in the recess of said hood adjustable to clamp the bared portion of said conductor and establish electrical connection therewith, and a spring contact member arranged in a central recess in said adjustable member, being electrically connected with said member at one end and having its outer end arranged to bear upon the contact on said insulator.

7. The combination with a spark-plug and an insulator projecting therefrom having an electrical contact at the outer'end thereof, of an insulator hood for inclosing said insulator and contact, an insulated electrical' conductor connected to said hood, a terminal contact connected to said conductor within said hood and arranged to cooperate with the contact on said insulator, and means for clamping said hood to said sparkplug comprising a yoke pivotally attached to the hood and engageable with a shoulder on the plug, and means for placing a resilient tension on said yoke to clamp the hood to the spark-plug.

8. The combination with a -spark-plug having an insulator and an electrical contact at the outer end thereof, of an insulator hood for covering said-insulator and contact, an insulated electrical conductor connected with said hood, a contact within the recess'of said *hood connected to said conduct-or and arranged to cooperate with the contact on said insulator, and clamping means for said hood on said spark-plug comprising a member embracing the hood, a yoke pivotally and longitudinally ad ustably attached to said embracing member and connected with said yoke and bearing on said embracing member to efi'ect the clamping of the hood to the casing.

9. The combination with a spark-plug having an insulator and an electrical contact at the outer end thereof, of an insulator hood for inclosing said insulator and contact, an insulated conductor connected With said hood, a contact Within said hood connected with said conductor and arranged.

metrically oppositely arranged resilient arms, a yoke member pivotally attached to said arms and laterally engageable with a shoulder on said casing, and a cam member pivotally connected to said yoke, operatively engaging said resilient arms to exert a pressure thereon and to resiliently clamp the hood to the casing.

' In testimony whereof I afix my signature.

ALBERT SCHMIDT. 

